fix: resolve settings API 500 errors

[Shravani-36]

Summary

Fixed the Settings API routes that were returning 500 Internal Server Error on the deployed dashboard.

This update improves Supabase user resolution and adds safer error handling for settings-related API routes so the Settings page loads correctly.

Closes #476

Type of Change

• Bug fix
• New feature
• Documentation update
• Refactor / code cleanup

Changes Made

• Fixed user resolution logic in resolveAppUser
• Improved Supabase query handling for missing users
• Added safer null/error handling in settings API routes
• Prevented API crashes when user records are unavailable
• Verified /dashboard/settings loads successfully locally
• Fixed settings fetch/update response handling

How to Test

Steps for the reviewer to verify this works:

1. Clone the repository
2. Add valid Supabase environment variables in .env.local
3. Run:

npm install
npm run dev

4. Open:

http://localhost:3000/dashboard/settings

5. Sign in with GitHub

6. Verify:

   • Settings page loads correctly
   • Public profile toggle works
   • Leaderboard toggle works
   • Linked GitHub accounts load successfully
   • No 500 errors appear in Network tab

Screenshots (if UI change)

N/A

Checklist

• Linked issue in summary
• npm run lint passes locally
• No TypeScript errors (npm run type-check)
• Self-reviewed the diff
• Added/updated tests if applicable

[vercel]

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[github-actions]

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